Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Other Commitments [Line Items]
Letters of credit outstanding, amount	$ 11.2		$ 11.2		$ 6.2
Capital lease obligations	17.3		17.3		23.0
Non cancellable operating leases arrangements
Other Commitments [Line Items]
Operating lease expenses	3.2	$ 2.9	6.3	$ 5.6
Deferred rent liabilities	$ 2.7		$ 2.7		$ 2.9
Maximum | Capital lease obligations
Other Commitments [Line Items]
Lease obligation interest rates	10.00%		10.00%
Letter of Credit
Other Commitments [Line Items]
Letter of credit, fee percentage					2.50%
Letter of Credit | Minimum
Other Commitments [Line Items]
Letter of credit, fee percentage			2.50%
Letter of Credit | Maximum
Other Commitments [Line Items]
Letter of credit, fee percentage			3.00%